ReadingMate Lets You Read on the Treadmill

Photonics.comApr 2013
WEST LAFAYETTE, Ind., April 18, 2013 — Do you ever get bored running endless miles on a treadmill and wish that you could read while working out? Well, now you can, thanks to a new system that steadies text on a display so you can read it as you sweat through the miles.

The system, called ReadingMate, counteracts the bobbing motion of a runner’s head by adjusting text on a monitor so that it appears still, said Ji Soo Yi, an assistant professor of industrial engineering and director of the Healthcare and Information Visualization Engineering Lab at Purdue University.

“Not many people can run and read at the same time,” said Yi, who developed the system with doctoral candidate Bum chul Kwon. “This is because the relative location of the eyes to the text is vigorously changing, and our eyes try to constantly adjust to such changes, which is burdensome.”

The researchers developed ReadingMate on the hypothesis that the primary impediment to reading while running is the head’s vertical movement. The new system enables a jogger, using goggles equipped with infrared LEDs, to read normal-size text on a small monitor mounted in front of the treadmill. An infrared camera captures the LEDs, tracking the runner’s bobbing head; the text is moved in unison with the head movement, as the human reflex to compensate for motion is taken into consideration.

Purdue industrial engineering doctoral candidate Bum chul Kwon demonstrates a new system that allows treadmill users to read while they run. The system, called ReadingMate, adjusts text on a monitor to counteract the bobbing motion of a runner’s head so that the text appears motionless. Courtesy of Purdue University/Mark Simons.
“Our eyes can accommodate vibration to a certain degree,” Yi said. “There are compensatory reflex mechanisms that tend to stabilize the head and eyes to maintain gaze and head position.”

To account for these reflexes, Kwon developed an algorithm to correctly move the text.

“You can't just move the text exactly in synch with the head because the eye is already doing what it can to compensate,” he said. “So you have to account for that compensation by moving the text slightly out of synch with the head motion.”

The system was tested by 15 students who carried out a “letter counting” task while running on a treadmill. The test required participants to count how many times the letter F occurred in two lines of text situated among 10 lines displayed on a computer monitor.

Participants who used ReadingMate demonstrated a higher accuracy compared with those in a control group.

“We also measured whether participants gave up on counting the letters because the task was too difficult,” Kwon said. “We often saw people giving up without ReadingMate, especially with certain font sizes and smaller spaces between lines.”

The system also could be used by heavy-equipment operators and aircraft pilots who experience turbulence and heavy shaking while reading information from a display, Kwon said. “ReadingMate could stabilize the content in such cases.”